4- Neurotransmitters and their Functions Flashcards
3 examples of small-molecule neurotransmitters
Acetylcholine
Dopamine
Serotonin
What type of synapses does acetylcholine use?
Cholinergic synapses
How does acetylcholine cause muscles to contract?
It changes the synapse shape to allow Na+ ions to enter, and causes depolarisation
2 types of receptors cholinergic synapses use
Nicotinic receptors and muscarnic receptors
What is an agonist?
A chemical that binds and activates a receptor
What is an antagonist?
A chemical that binds and blocks a receptor
What effects do raised acetylcholine levels in the brain have?
Positive effects on learning and memory
What are destroyed in Alzheimer’s disease?
Neurons
What do treatment drugs for Alzheimer’s disease increase?
Acetylcholine levels
Enzyme that breaks down acetylcholine
Acetylcholinesterase
Where is dopamine important?
In emotion and cognition
3 pathways that use dopamine
Mesolimbic pathway
Mesocortical pathway
Nigrostriatal pathway
What is the mesolimbic pathway involved in?
Drug abuse and addiction
What does the mesolimbic pathway respond to?
Rewards and motivation
Where is the nigrostriatal pathway implicated?
Parkinson’s disease
Where do neurons project to in the nigrostriatal pathway?
Basal ganglia and thalamus
Where is serotonin produced?
Raphe nuclei
What 4 things is serotonin implicated in?
Mood and sleep
Body temperature
Appetite
Metabolism
What does increasing levels of serotonin treat?
Depression and anxiety
2 examples of neuropeptides
Oxytocin and opioid peptides
What is oxytocin involved in?
Social bonding and interaction
What is oxytocin also known as?
The love hormone
How are opioid peptides distributed in the brain?
Widely
What are the best understood opioid peptides?
Endorphins
3 ways neuropeptides are different from small-molecule neurotransmitters
- Slower onset but much longer duration response
- Usually bind to metabotropic receptors
- Modulate enzyme effects
